TPS7A78 120-mA smart AC/DC low-dropout (LDO) linear voltage regulator | TI.com

TPS7A78 (PREVIEW) 120-mA smart AC/DC low-dropout (LDO) linear voltage regulator

 

Sample availability

Preproduction samples are available (PTPS7A7833PWPT, PTPS7A7836PWPT and PTPS7A7850PWPT). Order now

Description

The TPS7A78 improves the overall efficiency and standby-power in power-supplies in an easy-to-use, non-magnetic approach to AC/DC conversion. The TPS7A78 uses a capacitor-drop architecture to lower the AC source voltage before actively clamping the rectified voltage. The device then regulates this rectified voltage down to the application-specific operating voltage. The unique architecture of the device allows the standby power to be reduced to just a few 10s of milliwatts. The TPS7A78 switched-capacitor stage reduces power losses by stepping down the rectified input voltage by a factor of four and increasing the output-to-input current by the same ratio, as given by PIN ≅ POUT and VIN ≅ VOUT × 4. Compared to a traditional capacitor-drop (cap-drop) stage, this step down reduces input current, thus minimizing the value of the capacitance needed.

Electricity-metering applications, where the power supply must be reliable and magnetic tamper-proof, benefits from using the TPS7A78 because this device does not require external magnetics. This feature makes complying with IEC 61000-4-8 easier while minimizing magnetic shielding cost.

Additionally, the TPS7A78 also comes with a user-programmable, power-fail detection threshold that can provide an early alert to power failures and enable shutdown before complete power loss. The power-good indicator (PG) is also provided for sequencing or resetting a microcontroller.

The TPS7A78 is available in a 14-pin HTSSOP (PWP) package.


Features

  • Non-isolated power solution for ≥ 18 VAC RMS:
    • Up to 75% efficiency
    • Standby power consumption: 15 mW (typical)
    • Line-voltage, cap-drop capacitor as small as 1/4th the size of linear solutions
  • Available in fixed output voltages:
    • 1.3 V to 5 V (50-mV steps)
  • Power-fail detection
  • Power-good indication
  • 1% typical accuracy
  • Package:
    • 5-mm × 6.5-mm HTSSOP-14 (PWP)

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Parametrics

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Part number Order Output options Iout (Max) (A) Vin (Max) (V) Vin (Min) (V) Vout (Max) (V) Vout (Min) (V) Fixed output options (V) Package Group Features Regulated outputs (#) Operating temperature range (C) Thermal resistance θJA (°C/W) Approx. price (US$) Rating Accuracy (%) Iq (Typ) (mA) Package size: mm2:W x L (PKG)
TPS7A78 Order now Fixed Output     0.12     23     17     5     1.25     1.25
3.3
3.6
5    
HTSSOP | 14     Power-Fail Detect
Power Good
AC/DC Regulation    
1     -40 to 125     48     1.15 | 1ku     Catalog     2     0.28     14HTSSOP: 32 mm2: 6.4 x 5 (HTSSOP | 14)